Controlling device



Aug. 13, 1935. w. A SMITH, SR

CONTROLLING DEVICE Filed Sept. 26, 1934 I N VEN 7"0R. 'Il mijl- 51721711/ HIS ATTORNEY Patented Aug. 13, 1935 n 2,011,424 ooNTRoLLING DEVICE William A. smith, sr., Athens, Pa., assigner to Ingersoll-Rand Company, Jersey City,N. J., a corporation of New Jersey n Y Application September 26, 1913.4; v Serial'No, 745,511

5 Claims. (Cl. 1215-28) This invention relates touid actuated rock drills, and more particularly to afcontrolling device adapted to control vthe. action of the pres-- sure fluid distributing element of the rock drill.'

Oneobject of the inventionisrto enable the.,

movement of the pressure fluid distributing valve mechanism to be selectively accelerated or decelerated in order to cause the various'elements' or trains of elements of the rock drill to function ina manner best suited to produce maximum kdrilling results.v g

Another object is to maintain the consumption of pressure fluid to a minimum. I

Other objects will be in part obvious and in o --part pointed out -hereinaften AIn thedrawing accompanying this specifica tion' and' in whichy similar reference numerals refer to similar parts,` f

Figure l is a longitudinal elevation, in section, of a rock drill equipped witha controlling device, constructed in accordance with the practice of the invention, and v Figures 2 and 3 are transverse views taken through Figure 1 on theglines 2--2 and 3 3,

on respectively.

Referring to the drawlng,2 designates, in genv eral, a rock drillcornprising a cylinder 2| hav-l ing a piston chamber 22 `to accommodate a'reciprocatory hammer piston 23. The cylinder 2| is provided with the usual back head 24 which may be secured to the Vcylinder in any suitabley and ,well `known manner.

`Intermediate the ends of the piston `chamber 22 is a free exhaust port 25 which is controlledV `by the piston L23 anda closure is provided for lthe frontend of thepiston chamber by a wash-x er 26, the bore of which lserves as a vguide for a stem 2l of the'piston.

,'In thev portion ofthe cylinder lying rearward-r V, lyA of thepiston` chamber 22v is-an enlarged bore ZBpOntaining valve mechanism 29 and rotation mechanism ,30.The valve mechanism lies adjacent the rear end Vof the ppiston chamber22 and isseated upon ayplate 3| which serves as a'closure'for the rear 'gend' of the piston chamber.-y

:Theform of valve mechanism 29 selected for the purpose of illustration comprises a` valve chest 32 which restsupon the plate 3| and 4is bored to provideA front and rear valve chambersy 33andy 34. The valve chambers Whichfmay `be identicalr in all essential respects are in communication withi'each other at their'inner ends through channels 35 defined by'an intermediate interior portion ofthe valve 'chest anda bushA ing 36 extending therethrough and which is seated with its front end in the plate 3l and extends withits rear end intoa plate 3l interposed between the valve chest 32 `and the rotation mechanism 30.

.The pressure fluid employed vfor actuating the piston 23 is distributed to the endsof the` piston chamber by valves 38 and 39 disposed in the valve chambers 33 and34, respectively. Such pressure uid isjsupplied to the valve chambers by a supply passage or passages 40 in the valve chest 32, rotation mechanism 30 and the back head 24. The supplypassage 49 is in constant communication with the channels 35 and registers with a port 4| `in the wall of the throttle valve 42 in the back head 24. o

The throttle valve 42 may be of the rotary type having a central chamber 43 in constant compressure uid flows from the adjacent channelk 35k to the piston chamber` through a rear inlet passage 44.v Similarly, the valve 39 controls com- I munication between the rear channel 35 and a front inlet passage 45 which extends through the valve chest A32 and the cylinder 2| tothe front end ofthe piston chamber 22. o

The valves 38 and 39 are shown as being identicaland are, therefore, interchangeable so that inreassembling the valve mechanism either valve may be placed in either Valve chamber without in any way impairing or Varying the actionvof the rock drill. The valves are in the vform of sleeves journalled on the bushing 36 and carry peripheral flanges 46 of which the outermost surfaces constitute actuating areas 4-1. The confronting ends of the valves also serve as actuating surfaces 48 and are constantly exposed to pressure fluid tending to throw the valves to their open positions. Y

The actuating areas 4'|.are exposedintermittently to pressure fluid and the supply of pressure fluid thereto iscontrolled by the piston 23. To this en d the drill is provided Ywith tripper passages 49 and `5l] into which pressure yfluid is constantly supplied by leak ports 5| leading from a source of pressure iiuid supply, as for instance. from the supply passages 49. The tripper passage 49 opens intothe piston chamber 22 at a point forwardly of the free exhaust port 25 and has a branch Vpassage 52 through which pressure lluid may flow to the actuating area 41 of the valve 38. Pressure Huid entrapped in the tripper passage 59 flows through'a passage 53 in the valve chest to act against the actuatingarea 41 of the valve 39.

The rotation mechanism may be of a well known typev comprisinga rifle bar-54 which extends'through the bushing 36 and interloclrs with the piston 23. The rifle bar 54 has a. head55 `which carries spring-pressed pawls 56 for enf v gagement with the teeth 51 of a stationary ratchet ring 53 encircling the head 55.` i

n Owing to the arrangement of the ports and passages and the manner in which they are controlled'v and supplied with pressure iluid, actuating pres,- sure is entrapped in the tripper passages 49` and 5l)v and when the value of such pressure actingY I against an actuating area 41 predominates over that acting against the inner end of the valves they will be alternately closed and opened. More A specifically, when the -pston reaches a position` in the piston chamberto close-a tripper passage, the pressure fluid flowing into theclosed tripper passage acts against theactuating area 41 of the v associated valve and causes said valve to move to its closed position, as illustrated in Figure 1 of the drawing`.f v Y Infthe drawing the piston is shown in position kwto Vcover the tripper passage749 during the rear-V ward stroke of the piston. 'I'he pressure fluid flowing into said tripper vpassage ythen flows'` through the branch passage 52 and actsagainst the actuating area 41 of the valve 38 and main-A tains said'valve rmly seated, iinrclosed position; to prevent the ilow of pressure lluidfrom the adjacent channelf35 to the rear inlet passager 44. Meanwhile Vthe valve 39 remains open'to admit pressure fluid from the associated 'channel' 35 to vthe irontinlet passage45 and thus tothe front end ofA the piston chamber to drive Vthe pistonv rearwardly. v v

Shortly after covering the free exhaust port 25 the piston covers the tripper passage 50.' Presarsure fluid is then entrapped in the passage and will act against the actuating area41-of the valve f' 39'and'cause said valve to be thrown to its closed position before the piston again communicates s the front end of the piston chamber with the freeexhaust port 25. The piston will then be actuated 4 rearwardly by the expansive action ofthe presV`r sure fluid in the front end of the piston chamber and when it uncovers the free exhaust fport the' pressure fluid used for actuating it rearwardly,

together with that'acting against theactl'iatingk area 4'! of the valve 38, is exhausted to the atmosphere.` The pressure nuid in the channel 35 acting against they actuating area 48 of vthe valve 38 will then shift this'valve to Yitsopen position to again admit pressure fluid into the rear end ofthe` cylinder for driving the piston forwardly on its working stroke.

This movement of the valve n38 ftakes'place atv the time the piston 23 approaches the rearend of the piston chamber. The piston isthe'n reversed by the pressure iluid flowing into the piston chamber through the rear inlet passage 441 and driven on its'w'orking stroke.A During this movement of the piston thetripper passage 491s again covered before thefree exhaust portals uncovered and the pressure iluid entrapped in the tripper passage 49 causes the valve 38 to again shift to its closed position. Both valves will remain closed until' the rear end of the piston chamber is communicated a with theexhaust port 25,.Whereupon the valve 39 of the drill hole."

is shifted to its open position by pressure'iluid acting against its actuating area. 48. Pressure iluidA then ows through the front inlet passage 45 to again return the piston. v

In rock drills of which the piston has' opposed differential pressure areas to which the pressurey uidis valved individually by'one of a pluralityy of identical valves operating at the same stroke it has been found thatja considerable saving may be eiected in the matter of pressure fluid consumption and that the drill will be better suited for drilling different kinds of rock and at different ydepths ofi penetration by selectively controlling `thepoint in the cycle of operation of the piston at whichthe valve controlling theladmission of pressure fluid to the smaller pressure area of the f piston is actuated 'to its closed position. This is particularly true in rock drills in which the piston` is actuated throughout a portion of its stroke by expansion of theiactuating uid.

The smallerportion` of the pistonfchamber, in

thisV instance that :forwardly lof the piston, ob-'f viously requires' a lesser'volume'of pressure uid.

Unless the charge to the front' endis cut off somewhat earlier'during the 'rearward stroke of the piston, the admission of a given volume of pressure iluidlv into theV front end of the pistoniI chamber might'result'in discharging lluid directly` from supply through thevexhaust port without' accomplishing useful work, whereas, an

equal volume of pressure fluid/rearwardly of the is extremely difficult to 'effect thorough cleansing The detritus accumulates around the leading end ofV the drillf'steel and `retards the movement of therotati'on mechanism and consequently reduces the speed'of the piston'. In View of the foregoing considerations it is contemplatedV to yenabler the actionof the valve controlling admission of' pressure fluid to the' front end'of the piston chamber, in vthis instanceY the valve designated 39, to be so controlled that its closing movement may be selectively caused to take vplace early Vvor. late during the rearward stroke of the piston 23. Thermeans selected to make'such control of 'the valve 39 Vpossible r`comprises a manually operable' valve 59 disposed rotatably in the rear end of the cylinder 2| and pre-V ferably coaxially Withthe tripperp'assage 50.

In the front or innermost portion of the valve 59 is a bore 60 which'forms a. continuation of the tripper passiaigeV 50, and` a series of radial ports, in this instance two, designated Gland 62 in the valve 59"a1ord communication betweenthe bore 60 and the branch passage 53. The ports 6l andA 62 lie in the saine transverse planev andarey so` spaced with respect to each. otherv that only one port may register with-'the branch passage 53 at a time. The ports 6I and 62 are, moreover, of different sizes and increase in capacity in the order designated. i 'n v'I'he rear end 'of the valve V59 contains a spring `63 which Aseats against the back head 24 .to press the valve in the direction of thetripper passage 50, and on the same end of the Valve is a lateral lever 64 which extends exteriorly of the cylinderV 2| so` that-` it :may be conveniently grasped by the `operator to shift the valve 59; ofthe various controlling positions. Preferably, the rear end of the cylinder is provided with notches 65 and 66 which are so spaced with respect to each other that when the valve 59 occupies a controlling position the lever 64 lies in one of the notches to prevent unauthorized rotation of the valve 59.

When the rock drill is operating under normal drilling conditions and during which the action of the rotation mechanism is not unduly retarded, the control valve 59 occupies a position wherein the port 62 registers with the branch passage 53 so that a comparatively great volume of pressure iiuid passes from the tripper passage 50 to the actuating area 41 of the valve 39 within. a given period of time. The valve 39 will then be moved to its closed positionA immediately after the tripper passage 50 is covered by the piston 23 and the latter is then forced rearwardly by the expansive force of the pressure fluid forwardly thereof.

In the event that a collar of detritus forms around the drill steel, thus resisting the action of the rotation mechanism, the valve 59 is shifted to bring the smaller port 6l into registry with the branch passage 53. The introduction of a quantity of pressure uid into the branch passage 53 sufficient to predominate over that acting against the front end of the valve 39 will thereby be delayedv and the valve 39 will, in consequence, remain open for a slightly longer period of time during the rearward travel of the piston. A greater charge of pressure iiuid thus passes into the front end of the piston chamber and the shifting of the valve 39 may be delayed until the front end of the piston more nearly approaches the exhaust port 25. In this way a powerful charge of pressure iiuid acts against the piston to assure an adequate rotary movement of the working implement against which the piston operates.

I claim:

l. In a fluid actuated rock drill, the combination of a cylinder having a piston chamber and a piston in the piston chamber, means including a valve and passages controlled thereby for distributing pressure uid to the piston chamber, an actuating area on the valve, a conduit for supplying pressure fluid to the actuating area and being controlled by the piston, and means for selectively varying the rate of iiow of pressure fluid to the actuating area to vary the movement of the valve with respect to the movement of the piston.

2. In a fiuid actuated rock drill, the combination of a cylinder having a pistonA chamber and` a piston in the piston chamber, means including a valve and passagesv controlled .thereby for distributing pressure fluid to the piston chamber,` an actuating area on the valve, a conduit for`` supplying pressure fluid to the actuating area and being controlled by the piston, and an ad- ,instable valve controlling the passage and having a series of channels of different capacity for varying the rate of admission of pressure fluid to the actuating area.' 3. In a fluid actuated-rock. drill, they combination of a cylinder having a piston chamber and a piston in the piston chamber, means including a valve and passages controlled thereby for distributing pressure fluid to the piston chamber, g

an actuating area on the valve, a tripper passage controlled by the piston and leading to the actuating area, aleak passage yconstantly conveying pressure fluid into the tripper passage, a springpressed valve in the cylinder rotatable to different positions to control the tripper passage and having a series of channels of differentcapacity to vary the rate 4of admission of pressure fluid to the actuating area, and interlocking portions on the spring-pressed valve and the cylinder for holding said valve in placed position.

4. In a fluid actuated rock drill, the combination of a cylinder having a piston chamber and a piston in the piston chamber, a valve chamber, inlet passages leading from the valve chamber to the piston chamber, a pair of valves ink the valve chamber to control the inlet passages, each valve having an actuating area, conduits for supplying pressure uid to the actuating areas and being controlled by the piston, and means for selectively controlling the rate of flow of pressure through one conduit to the associated actuating area.

5. In a fluid actuated rock drill, the combination of a cylinder having a piston chamber and a piston in the piston chamber, a valve chestv having a valve chamber coaxial with the piston chamber, a valvefor distributingpressure'fluid to the piston chamber, an actuating area on the valve, a conduit in the cylinder and the valve chest for supplying pressure fluid to the aotuating area, and a manually operable valve in the cylinder having channels of different capacity for varying the rate of ilow of pressure uid through the conduit to the actuating area.

WILLIAM A. SMITH, SR. 

